Hellboy celebrates his 20th anniversary this month, and on April 1 a new hardcover collection, “Hellboy: The First 20 Years,” will arrive to mark the occasion.

The deluxe, oversized volume presents Hellboy creator Mike Mignola’s favorite covers and illustrations in gallery style and includes key pieces of his art such as his first sketch of the character.

Hero Complex readers can check out a selection of pages from the collection in the gallery above.

The character first appeared in print in 1994, when Dark Horse published “Hellboy: Seed of Destruction,” which introduced readers to the gruff half-demon who was summoned by the Nazis, rescued by the Allies and raised by the Bureau for Paranormal Research and Defense (and was inspired by Mignola’s father).

Hellboy’s popularity and evolution surprised even Mignola, however, who said he never would have guessed that the character would survive and thrive for two decades and star in two feature films — 2004’s “Hellboy” and 2008’s “Hellboy II: The Golden Army,” both of which were directed by enthusiastic Mignola fan Guillermo del Toro.

“When I started ‘Hellboy,’ I thought it wouldn’t work but at least I could look back on my deathbed and shakily point to this one thing and say ‘once I did a book that was about what I wanted to do,” Mignola told Hero Complex in an interview last week.

Mignola’s latest series featuring the character, “Hellboy in Hell,” sees the half-demon coming to terms with the fact that death hasn’t brought an end to his troubles, existential or otherwise.

“Hell is my place where I get to indulge. It’s my fantasy land,” Mignola said.